Great point. What I’m suggesting is that, based on the article, perhaps there’s an alternate or (more likely) supplemental explanation to microcavitation.
Maybe the baby bubbles bursting apply both exert a physical and a chemical (per the article’s discovery) effect on the substrate. If nontrivial, applying/developing different coatings that are more resistant to h2o2 could be useful in real world applications.
I really don’t know, but it’d be a logical next step for applied research!
Honestly I wouldn’t know, just musing! My background definitely isn’t in fluid flow.
A quick search suggests that cavitation modeling is actively being updated (src: https://aip.scitation.org/doi/10.1063/1.5052257), but I don’t know to what degree they’re refining them. Not my area of focus.
I wonder what peak concentration can be reached by cycling pure water through a micro-sprayer. I'd be skeptical if this could make rocket fuel, but it would be extremely cool if it could.
Turning ice asteroids into usable fuel would make space much more accessible.
Indeed. Used today for the attitude control thrusters on the Soyuz reentry capsule and as a monopropellant for the gas generators on the Soyuz booster rocket.
I took rocket fuel to just mean fuel rockets use. Some of these include highly refined kerosene (RP-1), methane, hydrogen and yes, hydrazine. The point was to ask if these microdoplets could be used to propel a rocket.
I agree, the news article shows that when they accidentally stumbled on this property they did the extra effort to further investigate (for example size of droplets). I have not yet read the actual paper, but I would at the very least expect the hydrogen to be traced to rule out other hypothetical explanations.
For example suppose the sprayer was a metal through which hydrogen can diffuse, perhaps sucked in osmotically, with the OH somehow stuck at that point on the metal surface, then over time all the surface "pores" would be clogged, but the bulk metal still osmotically sucks hydrogen, so perhaps the OH's on the surface are forced to recombine into H2O2 to make space. (I think their explanation is much more likely than mine, but it illustrates the importance of tracing all the chemical end products, to make sure the reaction is happening where one thinks it is happening. essentially: perform the experiment again in a continuous mode, in a closed recipient while monitoring hydrogen concentration. Continuous mode to prevent hydrogen gas diffused in metal components to be outgassed by say temperature effects of thermal cycling)
I think their explanation is very likely though. That the concentrations were higher in smaller droplets is a strong indicator that this is a surface effect (since volume of a droplet scales down with the third power in radius, while surface area scales down only with a second power in radius). Then remember that water is a polar molecule, and if they are anything like magnets, they don't like being parallel, so I would expect the electric dipole of a water molecule to try to lay in the plane of the surface on average, but as we all know, you cant comb a hairy ball!
That... seems to me to depend on whether the process is internal (within the droplet) or external (between the droplet and the external environment, which presumably contains oxygen). If it'd internal, the hydrogen has to go somewhere, so probably; if it's external, it could just be capturing extra Oxygen somehow, so maybe not.
I'd be interested to see whether the effect increases in a pure oxygen atmosphere, or goes away in pure nitrogen. Really, just try a bunch of different nitrogen/oxygen mixes. Maybe you can just oxygenate the shit out of bulk water and get the same effect.
For the record, I'm wrong. Hydrogen peroxide is H2O2, so it's just adding an extra oxygen from the air to the water molecule. I was thinking about Hydroxyl which is OH and would cause excess hydrogen gas.
You need H+ to raise the pH, like when you split water in HO- and H+. [1]
In this case they get H2O2 (neutral) so the H must be neutral, so they must combine to form H2 (neutral). (Perhaps the H radical can survive some time in water until it combine with other H and form the H2.)
[1] A small technical detail is that the reaction is 2 * H2O --> H3O+ + HO-, not H2O --> H+ + HO- , but H+ is the usual shorthand.
This sounds similar to Fleischmann–Pons 'Cold fusion' in 89 [0] (Could be related as the 30th anniversary?). It would be great if we could easily spit water to hydrogen and oxygen (unlimited clean fuel), but it comes down to those pesky chemical bonds, it takes a LOT of effort (energy) to pull them apart.
Could you elaborate on it please? It seems vapes create particles of comparable size to what is reported here. Also inhaling H2O2 can be toxic beyond a certain concentration. But I'm not sure what is the concentration here. The last paragraph is interesting though:
>Zare said, and it could lead to simpler ways to disinfect surfaces—simply spraying water microdroplets on a table or floor might be enough to clean it.
"I have to stretch the possible immediate practical applications of my research in order to better secure interest/funding/publicity, it's just part of the job"
Pretty much every every article like this has a couple sentences on practical applications that sound revolutionary. It's just part of how things are done and most of them will never come to fruition. Don't take it too seriously unless they have a proof of concept.
Someone mentioned the concentration was >1ppm. In other words, measurable, but negligible.
Vaping being bad for you is more directly comparable to smoking. You are inhaling hot water vapor and a bundle of chemicals into sensitive lung tissue. We've known that smoking is bad for you for decades. We don't really need new science to explain vaping.
Two scientists walk into a bar.
"I'll have H2O," says the 1st.
"I'll have H2O, too," says the 2nd.
Bartender gives them water because he is able to distinguish the boundary tones that dictate the grammatical function of homonyms in coda position, as well as pragmatic context.
I went down a bit of a rabbit hole with this yesterday. It's interesting--there's clearly some parts of the poem that are effective and lasting, while other parts aren't.
"thought was H20 was H2SO4" is identical in all the variants I found after the mid-20th-century. Most, but not all, have "What he thought was H20 was H2SO4". It seems like they "perfected" that part and it hasn't really changed since.
But the rest is very changeable--a few variants mention chemists and most mention a male name of some sort, but most have nothing else in common.
I Thought this was already known? I remember hearing about this in my Undergrad physics classes. At any time in liquid water, there are hydrogen bonds constantly breaking and rejoining between H-O, H2O, and H2O2.
Dr. Gerald Pollack has studied the "fourth phase" of water, which are sheets of H1O1. Water in this phase is electrically negative and forms the surface of bubbles/droplets, vesticules in cells, clouds, plasma in blood, & drives movement of water in plants. This book explains a number of phenomena with models backed by experiment.
